The Countertraffickers.(International Organization for Migration)

Stella Rotaru's cell-phone number is scribbled on the wall of a women's jail in Dubai. That's what a former inmate told her, and Rotaru does get a lot of calls from Dubai, including some from jail. But she gets calls from many odd places--as well as faxes, e-mails, and text messages--pretty much non-stop. "I never switch off my phone," she said. "I cannot afford to, morally." She looked at her battered cell phone, which has pale-gold paint peeling off it, and gave a small laugh.

Rotaru, who is twenty-six, works for the International Organization for Migration, a group connected to the United Nations, in Chisinau, Moldova. She is a repatriation specialist. Her main task is bringing lost Moldovans home. Nearly all her clients are victims of human trafficking, most of them women sold into prostitution abroad, and their stories pour across her desk in stark vignettes and muddled sagas of desperation, violence, betrayal, and sorrow.

Her allies and colleagues in this work are widely scattered. An ebullient Dubai prison officer named Omer, who calls Rotaru "sister," has been a help. So have Russian policemen, an Israeli lawyer, a Ukrainian psychologist, an Irish social worker, a Turkish women's shelter, Interpol, and various consulates and embassies, as well as travel agents, priests, and partner organizations, including an anti-trafficking group called La Strada, which has offices downstairs from Rotaru's and a dedicated victims' hot line.

Rotaru is often at the airport in Chisinau to meet those Moldovans who manage to get home with her help. In some cases, she goes to pick them up in Odessa, the Black Sea port in Ukraine--Moldova, an ex-Soviet republic, is half-encircled by Ukraine--where a twice-weekly ferry from Istanbul docks. If a victim's family is also present, there may be little or nothing for Rotaru to do. Or there may be a lot.

Rotaru doesn't look like a social worker. She has short, spiky hair of an unnatural brilliance--Red Planet, she told me cheerfully, is the brand name. She is dark-eyed, pale, direct in manner, and elfin in stature, even on the four-inch stiletto heels she always wears. In daylight, she wears vast sunglasses. Her fingernails are long and curved and painted with birds and animals and musical instruments. She talks on the phone and knocks out memos and documents and e-mails in four languages and three alphabets--Russian, Romanian, Swedish, and English. "When Stella is on a rescue call, we must be careful," Irina Todorova, one of four women who share an office with Rotaru, said. "First, she waves her hand for us to be quiet, and if we don't notice she pushes her chair back, and if we still don't shut up then she starts throwing things."

Brothel raids in other countries yield many of Rotaru's beneficiaries, as her clients are known. After a raid, she'll get calls from the detainees, or from cops, consulates, families, or friends--even, sometimes, from prostitution customers. "Rescue calls" tend to be more urgent. Women phone clandestinely, from captivity, and Rotaru may have only moments to get the information she needs. The women don't always have the information themselves; in extreme cases, they may not be sure what country they're in. Look out the window, Rotaru will say. Any sign you can see. Exact spellings. Look for an address on matchbooks, or McDonald's bags. What languages do the johns speak? If she can capture a number on caller I.D., it can be useful, although simply calling back without an all-clear is generally too dangerous.

At Christmastime last winter, a nineteen-year-old being held in a casino brothel in Cyprus called and texted Rotaru day and night. They talked about how she could escape from her pimp during the weekly medical exam that women working in the brothel received at a local hospital. Rotaru called someone in Cyprus at an N.G.O., who made sure that a trustworthy policeman would be there. The woman wore an ivory-colored headband, so that she would be recognized. The plan worked. A round-the-clock guard was stationed at the beneficiary's hospital room. Rotaru arranged for travel documents and an air ticket; the young woman flew home in time for New Year's Day, 2008.